Two classes of effector molecules which are critical for the progression of rheumatoid arthritis are pro-inflammatory cytokines and tissue degrading proteases. Recently, a family of kinases was described which is instrumental in controlling the transcription and translation of the structural genes coding for these effector molecules.
The mitogen-activated protein (MAP) kinase family is made up of a series of structurally related proline-directed serine/threonine kinases which are activated either by growth factors (such as EGF) and phorbol esters (ERK), or by IL-1, TNFα or stress (p38, JNK). The MAP kinases are responsible for the activation of a wide variety of transcription factors and proteins involved in transcriptional control of cytokine production. A pair of novel protein kinases involved in the regulation of cytokine synthesis was recently described by a group from SmithKline Beecham (Lee et al. Nature 1994, 372, 739). These enzymes were isolated based on their affinity to bond to a class of compounds, named CSAIDSs (cytokine suppressive anti-inflammatory drugs) by SKB. The CSAIDs, bicyclic pyridinyl imidazoles, have been shown to have cytokine inhibitory activity both in vitro and in vivo. The isolated enzymes, CSBP-1 and -2 (CSAID binding protein 1 and 2) have been cloned and expressed. A murine homologue for CSBP-2, p38, has also been reported (Han et al. Science 1994, 265, 808).
Early studies suggested that CSAIDs function by interfering with m-RNA translational events during cytokine biosynthesis. Inhibition of p38 has been shown to inhibit both cytokine production (eg., TNFα, IL-1, IL-6, IL-8) and proteolytic enzyme production (eg., MMP-1, MMP-3) in vitro and/or in vivo.
Clinical studies have linked TNFα production and/or signaling to a number of diseases including rheumatoid arthritis (Maini. J. Royal Coll. Physicians London 1996, 30, 344). In addition, excessive levels of TNFα have been implicated in a wide variety of inflammatory and/or immunomodulatory diseases, including acute rheumatic fever (Yegin et al. Lancet 1997, 349, 170), bone resorption (Pacifici et al. J. Clin. Endocrinol. Metabol. 1997, 82, 29), postmenopausal osteoperosis (Pacifici et al. J. Bone Mineral Res. 1996, 11, 1043), sepsis (Blackwell et al. Br. J. Anaesth. 1996, 77, 110), gram negative sepsis (Debets et al. Prog. Clin. Diol. Res. 1989, 308, 463), septic shock (Tracey et al. Nature 1987, 330, 662; Girardin et al. New England J. Med. 1988, 319, 397), endotoxic shock Beutler et al. Science 1985, 229, 869; Aslkenasi et al. Proc. Nat'l. Acad. Sci. USA 1991, 88, 10535), toxic shock syndrome, (Saha et al. J. Immunol. 1996, 157, 3869; Lina et al. FEMS Immunol. Med. Microbiol. 1996, 13, 81), systemic inflammatory response syndrome (Anon. Crit. Care Med. 1992, 20, 864), inflammatory bowel diseases (Stokkers et al. J. Inflamm. 1995-6, 47, 97) including Crohn's disease (van Deventer et al. Aliment. Pharmacol. Therapeu. 1996, 10 (Suppl. 2), 107; van Dullemen et al. Gastroenterology 1995, 109, 129) and ulcerative colitis (Masuda et al. J. Clin. Lab. Immunol. 1995, 46, 111), Jarisch-Herxheimer reactions (Fekade et al. New England J. Med. 1996, 335, 311), asthma (Amrani et al. Rev. Malad. Respir. 1996, 13, 539), adult respiratory distress syndrome (Roten et al. Am. Rev. Respir. Dis. 1991, 143, 590; Suter et al. Am. Rev. Respir. Dis. 1992, 145, 1016), acute pulmonary fibrotic diseases (Pan et al. Pathol Int. 1996, 46, 91), pulmonary sarcoidosis (Ishioka et al. Sarcoidosis Vasculitis Diffuse Lung Dis. 1996, 13, 139), allergic respiratory diseases (Casale et al. Am. J. Respir. Cell Mol. Biol. 1996, 15, 35), silicosis (Gossart et al. J. Immunol 1996, 156, 1540; Vanhee et al. Eur. Respir. J. 1995, 8, 834), coal worker's pneumoconiosis (Borm et al. Am. Rev. Respir. Dis. 1988, 138, 1589), alveolar injury (Horinouchi et al. Ant. J. Respir. Cell Mol Biol. 1996, 14, 1044), hepatic failure (Gantner et al. Pharmacol. Exp. Therap. 1997, 280, 53), liver disease during acute inflammation (Kim et al. J. Biol. Chem. 1997, 272, 1402), severe alcoholic hepatitis (Bird et al. Ann. Intern. Med. 1990, 112, 917), malaria (Grau et al. Immniuno Rev. 1989, 112, 49; Taverne et al. Parasitol Today 1996, 12, 290) including Plasmodium falciparum malaria (Perlmann et al. Infect. Immunol. 1997, 65, 116) and cerebral malaria (Rudin et al. Am. J. Pathol. 1997, 150, 257), non-insulin-dependent diabetes mellitus (NIDDM; Stephens et al. J Biol. Chem. 1997, 272, 971; Ofei et al. Diabetes 1996, 45, 881), congestive heart failure (Doyama et al. Int. J. Cardiol 1996, 54, 217; McMurray et al. Br. Heart J. 1991, 66, 356), damage following heart disease (Malkiel et al. Mol. Med. Today 1996, 2, 336), atherosclerosis (Parums et al. J. Pathol. 1996, 179, A46), Alzheimer's disease (Fagarasan et al. Brain Res. 1996, 723, 231; Aisen et al. Gerontology 1997, 43, 143), acute encephalitis (Ichiyama et al. J. Neurol. 1996, 243, 457), brain injury (Cannon et al. Crit. Care Med. 1992, 20, 1414; Hansbrough et al. Surg. Clin. N. Am. 1987, 67, 69; Marano et al. Surg. Gynecol. Obstetr. 1990, 170, 32), multiple sclerosis (M. S.; Coyle. Adv. Neuroimmunol. 1996, 6, 143; Matusevicius et al. J. Neuroimmunol. 1996, 66, 115) including demyelation and oligiodendrocyte loss in multiple sclerosis (Brosnan et al. Brain Pathol. 1996, 6, 243), advanced cancer MucWierzgon et al. J. Biol. Regulators Homeostatic Agents 1996, 10, 25), lymphoid malignancies (Levy et al. Crit. Rev. Immunol. 1996, 16, 31), pancreatitis (Exley et al. Gut 1992, 33, 1126) including systemic complications in acute pancreatitis (McKay et al. Br. J. Surg. 1996, 83, 919), impaired wound healing in infection inflammation and cancer (Buck et al. Am. J. Pathol. 1996, 149, 195), myelodysplastic syndromes (Raza et al. Int. J. Hematol. 1996, 63, 265), systemic lupus erythematosus (Maury et al. Arthritis Rheum. 1989, 32, 146), biliary cirrhosis (Miller et al. Am. J. Gasteroenterolog. 1992, 87, 465), bowel necrosis (Sun et al. J. Clin. Invest, 1988, 81, 1328), psoriasis (Christophers. Austr. J. Dermatol. 1996, 37, S4), radiation injury (Redlich et al. J. Immunol. 1996, 157, 1705), and toxicity following administration of monoclonal antibodies such as OKT3 (Brod et al. Neurology 1996, 46, 1633). TNFα levels have also been related to host-versus-graft reactions (Piguet et al. Immunol. Ser. 1992, 56, 409) including ischemia reperfusion injury (Colletti et al. J. Clin. Invest. 1989, 85, 1333) and allograft rejections including those of the kidney (Naury et al. J. Exp. Med. 1987, 166, 1132), liver (Imagawa et al. Transplantation 1990, 50, 219), heart (Bolling et al. Transplantation 1992, 53, 283), and skin (Stevens et al. Transplant. Proc. 1990, 22, 1924), lung allograft rejection (Grossman et al. Immunol. Allergy Clin. N. Am. 1989, 9, 153) including chronic lung allograft rejection (obliterative bronchitis; LoCicero et al. J. Thorac. Cardiovasc. Surg. 1990, 99, 1059), as well as complications due to total hip replacement (Cirino et al. Life Sci. 1996, 59, 86). TNFα has also been linked to infectious diseases (review: Beutler et al. Crit. Care Med. 1993, 21, 5423; Degre. Biotherapy 1996, 8, 219) including tuberculosis (Rook et al. Med. Malad. Infect. 1996, 26, 904), Helicobacter pylori infection during peptic ulcer disease (Beales et al. Gastroenterology 1997, 112, 136), Chaga's disease resulting from Trypanosoma crazi infection (Chandrasekar et al. Biochem. Biophys. Res. Commun. 1996, 223, 365), effects of Shiga-like toxin resulting from E. coli infection (Harel et al. J. Clin. Invest. 1992, 56, 40), the effects of enterotoxin A resulting from Staphylococcus infection (Fischer et al. J. Immunol. 1990, 144, 4663), meningococcal infection (Waage et al. Lancet 1987, 355; Ossege et al. J. Neurolog. Sci. 1996, 144, 1), and infections from Borrelia burgdorferi (Brandt et al. Infect. Immunol. 1990, 58, 983), Treponema pallidum (Chamberlin et al. Infect. Immunol. 1989, 57 2872), cytomegalovirus (CMV; Geist et al. Am. J. Respir. Cell Mol. Biol. 1997, 16, 31), influenza virus (Beutler et al. Clin. Res. 1986, 34, 491a), Sendai virus (Goldfield et al. Proc. Nat'l. Acad. Sci. USA 1989, 87, 1490), Theiler's encephalomyelitis virus (Sierra et al. Immunology 1993, 78, 399), and the human immunodeficiency virus (HIV; Poli. Proc. Nat'l. Acad. Sci. USA 1990, 87, 782; Vyakaram et al. AIDS 1990, 4, 21; Badley et al. J. Exp. Med. 1997, 185, 55).
Because inhibition of p38 leads to inhibition of TNFα production, p38 inhibitors will be useful in treatment of the above listed diseases.
A number of diseases are thought to be mediated by excess or undesired matrix-destroying metalloprotease (MMP) activity or by an imbalance in the ratio of the MMPs to the tissue inhibitors of metalloproteinases (TIMPs). These include osteoarthritis (Woessner et al. J. Biol. Chem. 1984, 259, 3633), rheumatoid arthritis (Mullins et al. Biochim, Biophys. Acta 1983, 695, 117; Woolley et al. Arthritis Rheum. 1977, 20, 1231; Gravallese et al. Arthritis Rheum. 1991, 34, 1076), septic arthritis (Williams et al. Arthritis Rheum. 1990, 33, 533), tumor metastasis (Reich et al. Cancer Res. 1988, 48, 3307; Matrisian et al. Proc. Nat'l. Acad. Sci., USA 1986, 83, 9413), periodontal diseases (Overall et al. J. Periodontal Res. 1987, 22, 81), corneal ulceration (Burns et al. Invest. Opthalmol. Vis. Sci. 1989, 30, 1569), proteinuria (Baricos et al. Biochem. J. 1988, 254, 609), coronary thrombosis from atherosclerotic plaque rupture (Henney et al. Proc. Nat'l. Acad. Sci., USA 1991, 88, 8154), aneurysmal aortic disease (Vine et al. Clin. Sci. 1991, 81, 233), birth control (Woessner et al. Steroids 1989, 54, 491), dystrophobic epidermolysis bullosa (Kronberger et al. J. Invest, Dermatol. 1982, 79, 208), degenerative cartilage loss following traumatic joint injury, osteopenias mediated by MMP activity, tempero mandibular joint disease, and demyelating diseases of the nervous system (Chantry et al. J. Neurochem. 1988, 50, 688).
Because inhibition of p38 leads to inhibition of MMP production, p38 inhibitors will be useful in treatment of the above listed diseases.
Inhibitors of p38 are active in animal models of TNFα production, including a muime lipopolysaccharide (LPS) model of TNFα production. Inhibitors of p38 are active in a number of standard animal models of inflammatory diseases, including carrageenan-induced edema in the rat paw, arachadonic acid-induced edema in the rat paw, arachadonic acid-induced peritonitis in the mouse, fetal rat long bone resorption, murine type II collagen-induced arthritis, and Fruend's adjuvant-induced arthritis in the rat. Thus, inhibitors of p38 will be useful in treating diseases mediated by one or more of the above-mentioned cytokines and/or proteolytic enzymes.
The need for new therapies is especially important in the case of arthritic diseases. The primary disabling effect of osteoarthritis, rheumatoid arthritis and septic arthritis is the progressive loss of articular cartilage and thereby normal joint function. No marketed pharmaceutical agent is able to prevent or slow is cartilage loss, although nonsteroidal antiinflammatory drugs (NSAIDs) have been given to control pain and swelling. The end result of these diseases is total loss of joint function which is only treatable by joint replacement surgery. P38 inhibitors will halt or reverse the progression of cartilage loss and obviate or delay surgical intervention.
Several patents have appeared claiming polyarylimidazoles and/or compounds containing polyarylimidazoles as inhibitors of p38 (for example, Lee et al. WO 95/07922; Adams et al. WO 95/02591; Adams et al. WO 95/13067; Adams et al. WO 95/31451). It has been reported that arylimidazoles complex to the ferric form of cytochrome P450cam (Harris et al. Mol. Eng. 1995, 5, 143, and references therein), causing concern that these compounds may display structure-related toxicity (Howard-Martin et al. Toxicol. Pathol. 1987, 15, 369). Therefore, there remains a need for improved p38 inhibitors.